Apparatus and method for dispensing sheets

ABSTRACT

Apparatus and method for dispensing individual sheets from a stack of sheets ( 10 ). A support ( 30 ) is provided for accommodating the stack of sheets in overlying parallel relationship. A suitable pickup device ( 20 ) overlying the support and having blowing means ( 62 ) is provided for producing airstreams over one end (A) of the upper sheet of the stack, such as to curl up this end and separate a portion of the upper sheet including this end from the stack. The pickup device also provides a holding force ( 60, 66 ), typically in the form of a suction force ( 60, 66 ) such as to hold at least part of this portion abutted against said pickup device, whereupon the airstreams may be terminated. A peeling mechanism ( 50 ) is also provided, having a clamping mechanism ( 70 ) for clamping the separated portion of the upper sheet, and adapted for displacing at least part of the sheet in a peeling motion in a direction substantially away from the original position of the end and/or the stack.

FIELD OF THE INVENTION

[0001] The present invention relates generally to apparatus andassociated method for the feeding of sheets, and more specifically forthe dispensing of sheets from a stack thereof. In particular, thepresent invention is concerned with feeding and manipulation of sheetsmade from limp and/or porous materials, including fabrics and paper,which may be optionally impregnated with a liquid material, such thatonly a single sheet is dispensed from the stack at a time in a reliablemanner and in a manner which prevents or at least significantly reducesthe possibility of more than one sheet being dispensed during a singledispensing action, and which further minimizes the production andejection of particles from the sheets into the atmosphere.

BACKGROUND OF THE INVENTION

[0002] The automated feeding or dispensing of sheets of soft paper orfabric presents some difficulty, generally because the softness orlimpness of the material, their tendency to adhere one to another, theirroughness and compressibility. The difficulties increase when dealingwith porous and/or impregnated materials.

[0003] Particularly with reference to the semiconductor industry, whereit is vital to clean items in a room such as machinery or furniture, oritems entering the clean room such as user's goggles, for example, thedispensing of fabric wipes used for such cleaning presents a particularproblem. As a sheet (or a bunch thereof) is pulled by a user, thefrictional action between the grasped sheet(s) and the remaining sheetsas a result of the shearing forces therebetween produces small and evenmicroscopic fragments or particles of fabric that tear off the sheetsand are expelled into the air. These fragments are potentially verydestructive in this industry, and the dispensation of the sheets to auser must be such as to minimise the production and dispersal of fabricparticles or fragments into the atmosphere of the clean room. Automaticdispensers in which an upper sheet is dragged with respect to a stack ofsheets is thus clearly unacceptable. Similarly, providing a system offolded intercalated sheets, in which as an upper sheet is pulled outfrom a box thereof, a second sheet is partially pulled out for easieruser access thereto is also unacceptable. In such a system, the fold ineach sheet produces particles, and the pulling action also induces shearforces between adjacent sheets which further produces and expelsparticles. A system comprising a spool or roll of material from which alength of sheet may be removed and cut off as required by a user is alsonot acceptable. In such a system, the cutting process also produces anddisperses particles into the air.

[0004] Furthermore, it is sometimes required in the clean rooms toimpregnate the sheets with alcohol to assist in the cleaning process,and to finish the process with a dry wipe. Typically, eitherpre-impregnated or “saturated” wipes are used, or dry wipes are sprayedmanually with alcohol. The first option requires two sets of wipes to bereadily available, one dry, and the other “saturated”, which hasrepercussions in the supply logistics. The second option results in agreat deal of excess alcohol being sprayed onto the surroundingenvironment and thus also into the atmosphere of the clean room. Thelatter option thus increases the levels of VOC (Volatile OrganicChemicals), which should be avoided.

[0005] Thus, in such applications as in the semiconductor industry, thesolution has been until now to manually dispense the towels or wipes,wherein a user grasps the sheets from a stack enclosed in a container ora pouch via an opening therein. Such an operation on average results inmore than one sheet being grasped with each grabbing action. Withpretreated or impregnated towels, such wastage can have significanteconomic repercussions. Nevertheless, in clean rooms of the microchipindustry as well as medical and/or surgical wards, and the like, wherehigh quality and expensive towels particularly impregnated with cleaningsolutions are routinely needed, the user is typically wearing gloves,which increases the difficulty in taking only a single towel at a time,and the capability of dispensing of towels one at a time presents aneconomic advantage.

[0006] In the clothing manufacturing industry, there is also a need formanipulating and dispensing standard sized and shaped pieces of cloth orother fabric. There is also a need to enable soft sheets to beautomatically provided to a user on demand, in a simple and reliablemanner.

[0007] The problem of automatic feeding of sheet material, particularlyfabrics, leather and other limp materials, and to a lesser extent paper,is discussed in U.S. Pat. No. 4,635,917, U.S. Pat. No. 4,708,333 andU.S. Pat. No. 4,703,926. In U.S. Pat. No. 4,635,917, a method andapparatus for feeding sheets is described for feeding fabrics from astack, comprising an arrangement for: engaging the opposite edges of theupper sheet of the stack by a pair of restrainer members; bringing apickup head into engagement with the upper sheet of the stack whileproducing airstreams from the pick-up head directed outwardly acrossopposite edges of the upper sheet of the stack; lowering the pick-uphead to depress the stack below the restrainer members whereby theairstreams cause the opposite edges of the upper sheet of the stack tocurl upwardly to clear the restrainer members; lifting the upper sheetfrom the stack; permitting the stack to rise so as to bring the nextsheet into engagement with the restrainer members, whereupon the stackis ready for feeding the next upper sheet. Thus, the intention is forthe upper sheet to be removed vertically from the stack by virtue of thelifting action of the airstreams, coupled with the vertical movement ofthe pick-up head. There are two main problems associated with thisarrangement. First, the airstreams, while providing initial separationof the ends of the upper sheet, are not inherently suitable formaintaining a hold on the ends of the sheet, which may then fall. Thisis exacerbated by the second problem. The airstreams only lift up theends of the sheet, but not the intermediate portion of the sheet. Thus,the action of vertically lifting the upper sheet may not be entirelysuccessful in separating the intermediate portion of the sheet from thenext sheet. Any adhesion or friction between the upper sheet and thenext sheet provides a resistance to the lifting action, and either morethan one sheet is thus lifted with the upper sheet from the stack, ormore likely, the lower sheets act as an anchor, effectively pulling downon the upper sheet, causing the ends thereof to be distanced from theairstreams and reducing their effectiveness, thereby resulting in acatastrophic disengagement of the upper sheet from the pick-up head. InU.S. Pat. No. 4,708,333, additional airstreams are provided from outsidethe stack and directed towards it to aid in the separation of the topsheet by the pick-up head. Nonetheless, the arrangements are alsosubject to the two problems discussed above. U.S. Pat. No. 4,703,926,assigned to the same assignee as the other two patents, is directed inparticular to an edge aligning device, and does not address theseproblems.

[0008] An aim of the present invention is to provide an apparatus andmethod for feeding or dispensing sheets that overcomes the disadvantagesof prior art feeding apparatuses and methods.

[0009] It is another aim of the present invention to provide anapparatus and method for feeding or dispensing sheets from a stack,particularly adapted for sheets made from soft and/or limp and/or porousmaterials.

[0010] It is another aim of the present invention to provide such anapparatus and method for reliably dispensing a single sheet with eachdispensing action.

[0011] It is another aim of the present invention to provide such anapparatus and method in which the sheets may be individually impregnatedwith a desired liquid prior to dispensing.

[0012] It is another aim of the present invention to provide such anapparatus and method wherein the various steps involved in thedispensing of a sheet thereby may be individually controlled.

[0013] It is another aim of the present invention to provide such anapparatus, in which the dispensing of sheets is conducted in aparticularly clean manner, minimising or eliminating the ejection offabric particles or fragments from the sheets

[0014] It is another aim of the present invention to provide such anapparatus particularly adapted for use in clean rooms such as of thesemiconductor industry and operating theaters, for example.

[0015] Other purposes and advantages of the invention will appear as thedescription proceeds.

SUMMARY OF THE INVENTION

[0016] The present invention relates to an apparatus for dispensingsheets comprising:

[0017] (a) a support for accommodating a stack of sheets in overlyingparallel relationship;

[0018] (b) a pickup device overlying said support and comprisingsuitable blowing means, typically in the form of air openings, forproducing airstreams over a first end of the upper sheet of the stackthat may be accommodated by said support, such as to curl up said endand separate a portion of said upper sheet including said end from thestack, and further comprising suitable suction means, typically in theform of apertures, for creating a suction force such as to hold at leastpart of said portion abutted against said pickup device;

[0019] (c) a peeling or peel-back mechanism having a clamping mechanismfor clamping the separated portion of the upper sheet and adapted fordisplacing at least a part of the sheet in a peeling motion with respectto a remainder of said stack that may be accommodated by said support,typically in a direction substantially away from said end and typicallytowards a second end of the sheets in longitudinally opposedrelationship to said first end.

[0020] In the preferred embodiment, the pickup head comprises adisplacement arrangement for reciprocally moving said pickup devicetowards and away from the stack that may be accommodated by the tray.The displacement arrangement is adapted for providing vertical as wellas horizontal motion to said pickup device. The pickup head may beconfigured to reciprocally rotate about a suitable axis such as toprovide a desired vertical and horizontal movement to a part of saidpickup head, wherein said part of said pickup head comprises saidblowing means and said holding means. The displacement arrangement maycomprise a piston driver that is electrically actuable and controllableby any suitable control means including suitable electric, electronic orcomputer means.

[0021] The holding means typically comprise suction means, and this maycomprise a cylindrical member having suitable apertures operativelyconnected to a suitable suction source, said cylindrical member beingsubstantially aligned with said end. The blowing means typicallycomprise suitable openings provided in a plenum chamber accommodated insaid pick up head, said openings being operatively connected to asuitable compressed gas or air source, such as an air compressorarrangement or air blower for example, such as to provide substantiallytangential airstreams with respect to said cylindrical member.

[0022] The suction means and the blowing means may be operativelyinterconnected, and may be incorporated in a fan or air blowerarrangement, wherein suction is provided by the inlet to the air blower,and airstreams by the outlet thereof.

[0023] The air compressor arrangement is preferably electricallyactuable and controllable by any suitable control means includingelectric, electronic or computer means.

[0024] The apertures are typically operatively connected to a suitablevacuum source, such as for example a suitable vacuum pump, ejector orsuction pump arrangement. Preferably, the pump arrangement iselectrically actuable and controllable by any suitable control means,including electric, electronic or computer means.

[0025] The clamping mechanism typically comprises a support memberhaving clamping means at each end thereof adapted for clamping saidseparated portion of said upper sheet, and a pair of arms substantiallyorthogonal to said support member pivotally mounted with respect to asuitable swinging axis. The clamping means may comprise jaws, forexample, or a substantially stationary clamping member adapted forclamping with respect to the cylinder after the pick up head separatesand holds one end of the sheet. Preferably, the clamping means or jawsare electrically actuable and controllable by any suitable controlmeans, including electric, electronic or computer means. The clampingmechanism is optionally displaceable, preferably via a swinging motion,by means of a suitable driving mechanism, which is preferablyelectrically actuable and controllable by any suitable control means,including electric, electronic or computer means.

[0026] The peeling or peel-back mechanism is preferably suitablysynchronised with said pickup device. The synchronization between thepick up head and the peeling mechanism may be provided by suitablemechanical means and/or other suitable synchronization means includingelectrical, electronic, or computer means.

[0027] The tray is preferably a horizontal tray, and preferably inhorizontal alignment and reversibly movable from a position outside theapparatus to a position inside the apparatus.

[0028] The apparatus preferably further comprises optional suitablespraying system for spraying at least one suitable liquid to a saidsheet, said spraying system being operatively connected to at least onesource of said liquids and comprising at least one nozzle adapted forspraying said at least one liquid. The spraying system may be adaptedfor spraying a said sheet after the sheet has been fully separated fromthe said stack, and is preferably synchronised with at least with saidpeeling system.

[0029] The synchronisations may be provided by suitable mechanicalmeans, such as for example including suitable mechanical linkage betweensaid pickup device and said peeling mechanism. Preferably, suchsynchronisations are provided by suitable synchronization means,including electrical, electronic or computer means.

[0030] Optionally, the spraying system further comprises suitable meansfor enabling any desired combination of said liquids to be sprayed inany desired relative proportions onto said sheet.

[0031] The spraying system may be operatively connected to the blowingmeans, wherein the blowing means generate suitable airstreams to carrythe liquid spray to the sheet. Preferably, such a spraying system may besuitably synchronized with the blowing means such as to enable a sheetto be sprayed after the sheet has been at least partially or fullyseparated from the stack.

[0032] Optionally, the holding means constitute said clamping mechanism.Optionally, the peeling mechanism is incorporated in said pick up head,and the peeling mechanism may include suitable means for swinging thepickup head with respect to the stack.

[0033] The present invention also relates to corresponding methods fordispensing sheets from a stack of sheets in overlying substantiallyparallel relationship, comprising:

[0034] (a) providing suitable airstreams over a first end of the uppersheet of the stack such as to curl up said first end and separate aportion of said upper sheet including said first end from the stack;

[0035] (b) creating a suitable holding force such as to hold said firstend abutted against a suitable pickup device, and terminating the saidairstreams;

[0036] (c) clamping the separated portion of the upper sheet in (b) andterminating the suction force;

[0037] (d) displacing the sheet by a peeling or peel-back motion withrespect to a remainder of the stack, typically in a directionsubstantially towards a second end of said upper sheet opposed to saidfirst end.

[0038] Said first end and/or said second end may each comprise a corneror an edge of the sheet, for example, or indeed any other part of thesheet, as required or desired.

[0039] Typically, the holding force comprises a suction force.Optionally, all of said sheet is displaced in a peeling motion from saidstack. Alternatively, part of the sheet is displaced in a peeling motionfrom the stack, and a remaining part of said sheet which is still inoverlying relationship with said stack is removed from the stack byproviding a force to the sheet in a direction substantially towards saidfirst end. This force may be provided by generating suitable airstreamsto impinge on said sheet.

[0040] The said first end comprises an edge or a corner of said sheet.

[0041] The method may further comprise the step (e) of impregnating theseparated sheet with a suitable liquid after the sheet has beenseparated, and/or the step (f) of releasing the separated sheet forcollection or further processing.

[0042] Step (a) may be effected by lowering a suitable pickup deviceuntil it rests gently on said upper sheet, said blowing means comprisinga cylindrical member having suitable openings for providing saidairstreams. The suction force in step (b) may be provided via suitableapertures in said pickup device operatively connected to a suitablevacuum source. Step (c) may be effected by means of a suitable peelingmechanism including a clamping mechanism having a pair of opposedclamping members, typically jaws, adapted for clamping said separatedportion of said upper sheet, and a pair of arms extending orthogonallyfrom said jaws and pivotally mounted with respect to a suitable swingingaxis. Step (e) may be effected by means of a spraying system adapted forspraying said liquid to the separated sheet.

[0043] Preferably, steps (a) to (d) are synchronised with respect to oneanother, and further preferably, at least steps (d) to (e) are suitablysynchronised with respect to one another. Steps (a) to (d) may be atleast partially synchronised by any suitable mechanical means, which mayinclude suitable mechanical linkage between said pickup device and saidpeeling mechanism. Alternatively, the synchronisation is provided bysuitable synchronization means, including electrical, electronic orcomputer means.

BRIEF DESCRIPTION OF THE FIGURES

[0044]FIG. 1 illustrates, in cross-sectional side view, the mainelements of a first embodiment of the present invention in thedispensing position.

[0045]FIG. 2 illustrates, in front perspective view, the embodiment ofFIG. 1.

[0046]FIG. 3 illustrates, in rear perspective view, the embodiment ofFIG. 1.

[0047]FIG. 4 illustrates, in cross-sectional side view, the mainelements of a first embodiment of the present invention in the clampingposition.

[0048]FIG. 5 illustrates, in front perspective view, the embodiment ofFIG. 4.

[0049]FIG. 6 illustrates, in rear perspective view, the embodiment ofFIG. 4.

[0050] FIGS. 7(a) to 7(h) illustrate schematically the operation of thefirst embodiment of the present invention.

[0051]FIG. 8 illustrates, in cross-sectional side view, the mainelements of a second embodiment of the present invention.

[0052]FIG. 9 illustrates, in bottom perspective view, the embodiment ofFIG. 8.

[0053]FIG. 10 illustrates, in cross-sectional upper view, the embodimentof FIG. 8 taken along A-A.

[0054]FIG. 11 illustrates, in top view, the embodiment of FIG. 8.

[0055]FIG. 12 illustrates, in cross-sectional side view, the embodimentof FIG. 11 taken along B-B.

[0056] FIGS. 13(a) to 13(d) illustrate schematically the operation ofthe second embodiment of the present invention.

DESCRIPTION

[0057] The present invention is defined by the claims, the contents ofwhich are to be read as included within the disclosure of thespecification, and will now be described by way of example withreference to the accompanying Figures.

[0058] The present invention relates to an apparatus and correspondingmethod for dispensing single sheets of a typically limp and/or porousmaterial from a stack thereof. Such sheets may be made from paper,fabric, leather or the like including towels, wipes and so on. Thepresent invention is characterised in that the sheets are each in turngrasped close to one free end, such as an edge or corner, thereof andpeeled away from the stack in a direction substantially perpendicular towhere this free end was, i.e., in a direction towards a second end whichis in opposed relationship longitudinally from the first, grasped end.In other words, the sheet is peeled back from the free end in a mannersuch as not to substantially introduce shear forces between the sheetand the adjacent sheet or surface below it, thereby minimising thepossibility of more sheets being removed together with the uppermostsheet, and thus minimising both wastage and the generation ofmicroscopic fibers and the like. Thus a “peeling” or “peel-back” motionis herein understood broadly as a motion by a sheet such that assuccessive adjacent portions of a first (or upper) sheet areprogressively separated from an adjacent second sheet or other surfacebelow the first sheet, the remaining portions of the first sheet arestill substantially in contact with the second sheet or surface, whereinsuch contact does not induce substantial sliding, shear or adhesiveforces due to the peeling motion. By substantial sliding shear oradhesive forces is meant that such forces do not result in the creationof particles from the sheet in quantities or concentrations greater thana desired threshold value. Such a threshold value generally depends onthe application for the apparatus of the invention, and thus where ahigher level of cleanliness is required, the threshold value will beless, and conversely, where the level of cleanliness may be relaxed, agreater amount of relative sliding motion between sheets may betolerated. Generally, such peeling motions involve a degree of motion byone end (edge or corner, for example) of the sheet towards the oppositeedge of the sheet, with possibly some degree of folding of the sheetover itself, while typically at the opposite end of the sheet there islittle or no substantial relative motion between the uppermost sheet andthe sheets below it until the last moment when the end of the uppermostsheet is fully peeled form the stack of sheets. Accordingly, such apeeling motion substantially reduces or removes the formation andexpulsion into the atmosphere of sheet fragments and particles. In somecases though, the peeling motion may be provided for part of the lengthof the sheet, and the last part of the sheet separated from the nextsheet in a different manner, as will be further described hereinbelow.

[0059] The present invention thus relates to an apparatus for dispensingsheets comprising:

[0060] a support for accommodating a stack of sheets in overlyingparallel relationship;

[0061] a pickup device overlying said support and comprising suitableblowing means, typically in the form of first air openings, forproducing airstreams over one end, including an edge or corner, forexample, of the upper sheet of the stack such as to curl up said end andseparate said end from the stack, and further comprising suitablesuction means or the like, typically in the form of apertures connectedto a suction or vacuum source, for creating a suction force such as tohold said end abutted against said pickup device; and

[0062] a peeling mechanism having a clamping mechanism for clamping theseparated portion of the upper sheet and adapted for displacing at leastpart or all of the sheet in a peeling motion with respect to a remainderof said stack that may be accommodated by said support, typically in adirection substantially away from said end, that is, towards an opposedend of the sheet.

[0063] Thus, referring to the figures, in particular FIGS. 1 to 6, afirst embodiment of the dispensing apparatus according to the presentinvention is generally indicated at (100) and comprises a suitablehousing (200) (shown schematically as a dotted line in FIGS. 1 and 4)adapted for accommodating a pickup device (20), a peeling mechanism(50), and a support in the form of a horizontal tray (30) for holding astack of sheets (10). Each said sheet (10) is typically rectangularhaving a first free edge (A) and a second free edge (B) in parallelopposed relationship, and orthogonal thereto third and fourth edges (C)and (D), with corners between adjacent edges. In some embodiments, thesheets may be in any other desired shape, wherein the apparatus (100) iscorrespondingly adapted for these shapes, typically in that the tray(30) comprises a suitable shape for accommodating the sheets and/or inthat the pickup device (20) having suction means and blowing means wherenecessary to pick up a desired end of the sheets, and/or in that thepeeling mechanism (50) is suited for clamping the raised part of thesheets, typically in a manner similar to that described herein withrespect to sheets (10), mutatis mutandis. The sheets (10) may be madefrom any type of flexible and/or limp and particularly, but not limitedto porous material, including paper tissue paper, flexible plastic,fabric, leather. The sheets may also be optionally pre-impregnated witha suitable liquid, such as alcohol, detergent, soap, disinfectant, forexample, or may be individually sprayable with any suitable liquid justbefore delivery to the user.

[0064] The tray (30) is typically horizontal and sheets can bevertically stacked thereon in horizontal arrangement. In otherembodiments the tray may be adapted to accommodate sheets in verticalarrangement or indeed in any inclined arrangement, in a similar mannerto the horizontal arrangement, mutatis mutandis. In the firstembodiment, the tray (30) has an upper open end and is slidable orotherwise moveable, typically in a substantially horizontal direction,from a position outside the housing (200), wherein the tray (30) may bereplenished with a stack of generally horizontally-laid overlying sheets(10) as required, to a position inside the housing (200), generallybelow the pickup device (20) and peeling mechanism (50). The tray (30)preferably comprises an internal floating bottom end that is urgedupwards via springs or the like, such as to move the stack of sheets(10) in an upward direction to compensate for the decrease in height ofthe stack as sheets (10) are progressively dispensed thereof by theapparatus (100). Thus, the uppermost sheet (10′) of the stack ispreferably maintained at generally the same position with respect to thehousing (200), regardless of the number of sheets (10) remaining in thestack. Other mechanisms are known in the art for elevating the upper endof the stack with respect to a suitable point in the housing and do notneed to be further described herein. Where the apparatus (100) does notcomprise such a height-maintaining mechanism for the stack of sheets(10), the apparatus (100) may instead compensate for the increasingdepth location of the uppermost sheet (10′) as the stack is used up.Such compensation mechanisms are known in the art for progressivelylowering the pick-up head with respect to the upper end of the stack anddo not need to be further described herein

[0065] The pickup device (20) comprises a displacement arrangement fordisplacing a pick up head (22) in relation to the stack of sheets, As isfurther described below, the displacement arrangement in this embodimentprovides reciprocating and primarily vertical motion to the pickup head(22), enabling the same to be alternately raised from and lowered to thestack of sheets (10). In other embodiments, the pickup device maycomprise a displacement arrangement that provides a rotational motion tothe pickup device such that a part of the pickup device can bevertically and horizontally moved as required.

[0066] In the first embodiment, the displacement arrangement is in theform of a piston drive (40) having a lower free end (42) connected tosaid pick-up head (22), and an upper end (44) anchored to a fixed point(110) in the housing (200). Referring in particular to FIGS. 1, 4 and7(a) to 7(d), the pickup head (22) comprises a pad member (24) and acylindrical member (60) connected thereto, which are arranged for gentlyresting on or close to the upper sheet (10′) of the stack of sheets (10)when the pickup device (20) is lowered thereonto. The cylindrical member(60) is aligned such that its longitudinal axis is substantiallyparallel to and orthogonally displaced from the first free edge (A) ofthe upper sheet (10′). The said cylindrical member (60) is typically alittle shorter than the width of the sheets (10), as defined by thespacing between edges (C) and (D) thereof.

[0067] The pickup head comprises suitable blowing means for generatingat least one suitable airstream over the upper sheet during operation ofthe head. The blowing means is typically in the form of nozzles or thelike operatively connected to a suitable compressed gas source, which istypically a compressed air source including, for example, compressed airbottles or a suitable air compressor such as a fan or air blower, forexample. Thus, in the first embodiment, the pad member (24) issubstantially hollow with closed longitudinal ends, and thus forms aplenum chamber (21) which is connectable to a source of pressurised air.The plenum chamber (21) comprises a longitudinal slit, or preferably aseries of slits, nozzles or openings (62) in spaced arrangement alongits length. The openings (62) provide a series of airstreams along theupper surface of the upper sheet (10′) of the stack in a directiontowards the edge (A), when the pickup head (22) is resting on sheet(10′), and tangential to the cylindrical member (60). The effect ofproviding this series of airstreams is to curl up the free end (A′) thatcomprises the said edge (A) of the upper sheet (10′) in an upwarddirection towards the cylindrical member (60), and thus separate thisend (A′) of the upper sheet (10′) from the next sheet (10) directlybelow it, as illustrated in FIG. 7(b). As the airstreams follow theupwardly curving surface of the cylindrical member (60), a liftingeffect is created with respect to the end (A′) of sheet (10′). Asuitable compressed gas or air source (not shown) is thus operativelyconnected to the pad member (24) to provide the airstreams.

[0068] The pickup head is characterized in further comprising a suitableholding means for temporarily adhering the lifted end of the upper sheetto the pickup head after the end has been separated from the stack bymeans of the blowing means. The holding means are preferably in the formof suction means. Thus, the cylindrical member (60) typically comprisesa series of apertures (66) in spaced arrangement along its length. Theseries of apertures (66) are operatively connected to a suitable vacuumsource (not shown) and are typically positioned at the lower part of thecylindrical member (60), or close to the bottom and preferably displacedto the right as viewed in Fig. 1. The location of the apertures (66) andthe strength of the suction provided thereat by the suction source issuch as to suck the free end (A′) towards the cylindrical member (60)after the end (A′) has been curled up by means of the aforesaidairstreams, and to then hold the upper sheet (10′) firmly against thecylindrical member (60) via this end (A′), as illustrated in FIG. 7(c).At this point, while suction is maintained via said apertures (66), theairstreams provided via openings (62) are terminated. Thus, in thenormal course of events, the end (A′) is maintained firmly abuttedagainst the cylindrical member (60) until the suction to the apertures(66) is terminated. The piston drive (40) then lifts the pickup head(22), separating a larger portion (X) of the upper sheet (10′) from thestack, as illustrated in FIG. 7(d). At the same time, a concurrenthorizontal motion is also provided by the piston drive (40) in adirection towards the edge (B) such as to prevent the upper sheet (10′)being dragged in the opposite direction by virtue of the lifting actionvia edge (A), which could otherwise crumple the upper sheet (10′) and/orcause adhesion or other interference with lower sheets (10). In otherembodiments, rather than employing suction to hold the upper sheet (10′)with respect to the pick up device (20), the apparatus (100) mayalternatively comprise any suitable means for holding the upper sheet(10′), such means including any suitable mechanical means such clampingmeans or grasping means, for example.

[0069] While the beginning of the peeling action by means of the pick-uphead, i.e., the separation stage of the process where an end of thesheet is separated from the stack, has been described above with respectto one edge (A) of the sheet, the sheets may be picked up and peeledfrom any suitable end of the sheet. For example, the sheets may beoriented such that a corner thereof, rather than an edge thereof, isaligned with respect to the pickup head (20). Thus, the air openings(62) may provide a series of airstreams along the upper surface of theupper sheet (10′) of the stack in a direction towards this corner (A),when the pickup head (22) is resting on sheet (10′), curling up thisfree corner in an upward direction towards the cylindrical member (60),thus separating this corner of the upper sheet (10′) from the next sheet(10) directly below it. As the airstreams follow the upwardly curvingsurface of the cylindrical member (60), a lifting effect is created withrespect to the end of sheet (10′) that comprises this corner. As before,this free corner is then sucked towards the cylindrical member (60), andthe upper sheet (10′) is firmly against the cylindrical member (60) viathis corner. At this point, while suction is maintained via saidapertures (66), the airstreams provided via openings (62) areterminated. Thus, in the normal course of events, the corner ismaintained firmly abutted against the cylindrical member (60) until thesuction to the apertures (66) is terminated and the pickup headcontinues as described before, mutatis mutandis. Similarly, round oroval sheets, or indeed sheets of any shape may be picked up in a similarmanner as described above, mutatis mutandis, by first blowing airstreamsover one end, and then sucking or otherwise holding the end in abutmentwith the cylindrical member (60).

[0070] Referring in particular to FIGS. 7(e) to 7(h), the peelingmechanism (50) is characterised in having means for grasping or clampingthe end (A′) after this has been separated from the stack of sheets(10), and in then progressively separating the upper sheet (10′) fromthe stack in a peeling motion, typically, or at least in part, in ageneral direction towards the opposite free end or edge (B) of the sheet(10′). This type of relative movement between the upper sheet (10′) andthe stack introduces substantially no tendency for sliding between theupper sheet (10′) and the next sheet (10) directly below it, therebygenerally ensuring that no additional sheets (10) are removed togetherwith the upper sheet (10′). The peeling action provided by the peelingmechanism (50) comprises primarily a substantially horizontaldisplacement of the free end (A′) in a direction towards the second freeedge (B), such that virtually no shearing forces are introduced betweenthe upper sheet (10′) and the sheets (10) below it, which wouldotherwise stick thereto due to frictional forces thereby set up.Furthermore, it is often encountered in a stack of sheets that adjacentsheets (10) stick to each other because of electrostatic attraction, ordue to any other effect. In the present invention, the peeling motionprovided by the peeling mechanism “unsticks” the upper sheet (10′) fromthe adjacent sheet (10) thereto once the free end (A) of the upper sheet(10′) has been successfully separated form the stack by means of thepickup device (20). Furthermore, this peeling motion also prevents or atleast substantially reduces the production of particles or fragmentsfrom the material of the sheets.

[0071] The piston drive (40) may be pneumatically or hydraulicallyoperated. Alternatively, and preferably, the required motion to thepickup head (22) is provided by any suitable electrically actuatedarrangement, which may be controlled by any suitable electric,electronic or computer means. Similarly, the airstreams and vacuumprovided by means of openings (62) and apertures (66), respectively, maybe provided by a suitable gas source and vacuum source, respectively,but are preferably provided by means of electrically operated suitablecompressors (including air blowers or fans) and vacuum pumps,respectively, which may be controlled by any suitable electric,electronic or computer means.

[0072] Alternatively, the piston drive (40) may be replaced by anysuitable mechanical mechanism capable of providing the require motionsto the pick up head (22), and such mechanisms are known. In particularsuch a mechanical mechanism is actuable electrically and controllable byany suitable electric, electronic or computer means, to provide a morecompact apparatus (100).

[0073] In the first embodiment, the peeling mechanism (50) comprises aclamping mechanism (70) which is reciprocally movable between a first,dispensing position (DP) to a second, clamping position (CP),illustrated in FIGS. 1 and 4 respectively. The clamping mechanism (70)is adapted to clamp the upper sheet (10′) along the edges (C) and (D),in particular of the portion (X), once this portion of the upper sheet(10′) has been separated and lifted by means of the pickup device (20),described hereinbefore. Of course, where the sheets (10) are or adifferent shape, or indeed oriented such as to present a corner ratherthan an edge with respect to the cylindrical member (60), the clampingmechanism (70) is adapted for clamping lateral portions of the sheets,wherein said lateral portions are typically in orthogonal relationshipto said end of the sheets that is picked up via the pickup device (20).In the first embodiment of the present invention, and referringparticularly to FIGS. 1, 3 and 4, the clamping mechanism (70) comprisesa pair of clamping jaws (72), one said clamping jaw (72) beingaccommodated at each of the ends of a support bar (73). The support bar(73) comprises a suitable actuation mechanism (74), which may includefor example an electrical actuator including a solenoid, or a hydraulic,pneumatic or other suitable actuator, enabling the jaws (72) toselectively and alternately open or close against the support bar (73).The support bar (73) is in a generally parallel juxtaposed and spacedrelationship with respect to the said cylindrical member (60). Thesupport bar (73) is somewhat longer than the width of the sheets (10),and thus the ends of the support bar (73) extend beyond the edges (C)and (D) of the upper sheet (10′). The support bar (73) is joined at itsends to two spaced parallel C-shaped arms (75), which are rotatablymounted to a shaft (80), which is substantially parallel to the supportbar (73). The shaft (80) is fixed in the housing (200), and enables thesupport bar (73) to be rotated with respect thereto about axis (82) ofthe shaft (80) via arms (75), such as to displace the support bar (73)vertically and horizontally between the said dispensing position (DP)and the said clamping position (CP).

[0074] Referring particularly to FIGS. 4 and 7(e) to 7(h), in the saidclamping position (CP), the support bar (73) is located to the right ofthe portion (X) of the upper sheet (10′) (as viewed in FIG. 4), suchthat the jaws (72) in the open position are to the left of portion (X).Thus, when the jaws (72) are closed, they grip portion (X) of the uppersheet (10′) against the support bar (73). After the clamping mechanism(70) clamps the upper sheet (10′), the pickup device (20) may disengagefrom the end (A′), typically by terminating suction at the apertures(66).

[0075] As the support bar (73) swings via a suitable driver (not shown)from the clamping position (CP) to the dispensing position (DP) aboutaxis (82), the support bar (73) undergoes a net horizontal displacementin a direction towards the second free edge (B) of the upper sheet(10′), thereby causing the upper sheet (10′) to initially substantiallyfold over itself and thus peel away from the adjacent sheet (10) untilthe said upper sheet (10′) is fully displaced horizontally from itsadjacent sheet (10), which of course is now upper in the stack. At thesame time, the support bar (73) also undergoes a net verticaldisplacement in the upward direction such that the edge (B) is nowhanging below the support bar (73), and a sheet in this position isillustrated in FIGS. 1 and 7(h) as sheet (10″). Thus, at the dispensingposition (DP), the previously upper sheet (10′) is completely removedfrom the stack and is hanging, by means of the clamping mechanism (70),over a collection trough (90), as indicated at (10″) in FIGS. 1 and7(h). At this point, the actuation mechanism (74) is disengaged, andthis sheet (10″) falls by gravity into the trough (90). The trough (90)is in open communication with the outside of the housing (200) via asuitable opening (95), enabling a user to access the sheet thusdispensed. Alternatively, the hanging sheet (10″) may be furthermanipulated by suitable mechanisms is so required.

[0076] In other embodiments, the peeling mechanism (50) may comprise anyother suitable means for providing the required peeling motion to thesheet (10′) by grasping or clamping the separated end (A′) thereof. Forexample, in place of the clamping mechanism (70) described herein, thepeeling mechanism (50) may comprise a pair of belts driven by suitabledrive means, the belts being located one on either side of the sheet(10′), parallel to edges (C) and (D) respectively. The belts may eachcomprise one or more grasping or clamping jaws, and comprise a path ofrevolution such that one jaw on each belt is synchronised to clampportion (X) of the sheet (10′) along edges (C) and (D), and to then peelthe sheet (10′) to the dispensing position (DP) in an appropriatemanner.

[0077] The peeling mechanism (50) may be pneumatically or hydraulicallyoperated. Alternatively, and preferably, the required motion to theclamping mechanism (70) including the jaws (72) is provided by anysuitable electrically actuated arrangement, which may be controlled byany suitable electric, electronic or computer means.

[0078] While the sheet (10″) is hanging in the dispensing position (DP),optional spraying system (300) may be provided for spraying a suitableliquid onto the sheet (10″) just before being dropped into the trough(90). Such spraying system (300) may be advantageous in cases, forexample, where it is desired to dispense disinfectant-impregnatedhand-towels, wipes impregnated with cleaning solutions including forexample alcohol, or the like, in particular where the liquid is volatileand thus evaporates relatively quickly from the sheet, renderingpre-impregnated sheets unsuitable. The spraying system (300) ispreferably operatively connected to a suitable electric, electronic orcomputer controller. The spraying system (300) may be adapted forautomatically spraying each sheet (10″) just before being dispensed.Alternatively, a manual interaction facility may be incorporated intothe spraying system (300) to enable the user to spray any particularsheet (10″) as desired. Alternatively, the spraying system (300) may becontrolled such as to spray a number of sheets in succession, and thento desist from spraying for another succession of sheets, for anydesired frequency and permutation of sprayed sheets and dry sheets,according, by suitably programming a computer control means operativelyconnected to the spraying system (300).

[0079] The spraying system (300) may comprise one or more sprayingnozzles (350) in communication with one or more suitable liquid sources(not shown) that it is desired to spray onto the sheets. Suitablecontrol means may also be provided for enabling the user to choose anyone of a plurality of such liquids to be sprayed onto the sheet (10″).Optionally, such control means may also enable the user to mix two ormore such liquids via dedicated or shared nozzles (350) in any desiredquantities or proportions. Thus, for example, the spraying system (300)may comprise a nozzle (350) operatively connected to a source ofalcohol, and another nozzle (350) operatively connected to a source ofdeionised or distilled water. Electrically operated valves, for example,may then be used, in conjunction with a controller, to enable eitherwater or alcohol, or indeed any mixture of the two, to be sprayed ontothe hanging sheet (10″), according to user need or desire.

[0080] Thus, the present invention also relates to a method fordispensing sheets from a stack of sheets in overlying substantiallyparallel relationship, comprising:

[0081] (a) providing suitable airstreams over one end of the upper sheetof the stack such as to curl up said end and separate a portion of saidsheet including said end from the stack;

[0082] (b) creating a suitable holding force, typically but not limitedto a suction force, such as to hold said edge abutted against a suitablepickup device, and terminating the said airstreams;

[0083] (c) clamping the separated portion of the upper sheet in (b) andoptionally terminating the holding force;

[0084] (d) displacing at least a part of the sheet by a peeling motionin a direction substantially towards a second end opposed to said end.

[0085] Thus, the apparatus (100) typically operates cyclically, whereinin each cycle a single sheet (10) is dispensed from the stack as aresult of two operations. In the first operation, as illustrated inFIGS. 7(a) to 7(d), the piston drive (40) is in the lower position, withthe pickup head (22) gently resting on the upper sheet (10′) which is tobe removed from the stack. Airstreams provided by the openings (62)initially curl the free end (A′), which may comprise, for example, acorner or edge of the sheet (10′), separating the end (A′) from theadjacent sheet (10), bringing the end (A′) towards the cylindricalmember (60). Suction is then provided via apertures (66), causing theend (A′) to be firmly held against the cylindrical member (60),whereupon the airstreams are terminated. The piston drive (40) thenmoves upwards and sidewards to its upper position, thereby separating agreater portion (X) of the upper sheet (10′) in a peeling non-slidingmotion.

[0086] Then, in the second operation, and as illustrated in FIGS. 7(e)to 7(h), the peeling mechanism (50) operates by displacing the clampingmechanism (70) from the dispensing position (DP) to the clampingposition (CP) about axis (82), typically via a swinging motion. The jaws(72), in the open position, thus move past the portion (X) of the uppersheet (10′), whereupon the actuating mechanism (74) closes the jaws(72), thereby clamping the sheet (10′) close to the first edge (A). Atthis point the suction via apertures (66) is terminated, and the sheet(10) is held only via the jaws (72). The clamping mechanism (70) is thenswung back about axis (82) from the clamping position (CP) to thedispensing position (DP), peeling the upper sheet (10′) from the stack,and holding the sheet (10′) in a substantially vertical position,illustrated as (10″), at which stage it may be optionally impregnatedwith liquid via spraying system (300). The hanging sheet (10″) may thenbe dropped into trough (90) for collection by the user. Alternatively,the hanging sheet (10″) may remain hanging until a user requires thesheet (10″), whereupon as a user's hand approaches the sheet (10′″) thisis disengaged from the clamping mechanism (70), enabling the user tograsp and remove the sheet (10″). Thus, suitable detection means such asa photocell arrangement for example, may detect the entry of the user'shand into the apparatus (100) via opening (95), and the detection meansthen provide a suitable signal for a controller to release jaws (72).

[0087] Alternatively, in the second operation the clamps (70) may beconfigured so that instead the free end (A) is moved in a clockwisedirection (with respect to FIGS. 7(e) to 7(g), such as to minimize thesliding motion between the remaining part of the uppermost sheet and thesheet below it, and blowing means can then be provided to blow end (B)of the sheet towards the front of the device, oriented on the left partof FIG. 7(g).

[0088] Thus, the second operation needs to be properly synchronised withthe first operation in order that the sheet (10′) is in the correctposition for clamping via the clamping mechanism (70) before the jaws(72) are activated. Similarly, the first operation has to besynchronised with the second operation so that the pickup device (20)does not descend onto a new upper sheet (10′) on the stack until theclamping mechanism (70) has been cleared from the clamping position(CP). Further, the spraying system (300) should not normally startspraying liquid until the end of the second operation, and prior todropping the sheet (10″) into the trough (90).

[0089] Similarly, there is little need in starting the airstreams untilthe pickup head (22) is resting gently on or is in close proximity tothe stack, and should not be terminated until adequate suction has beenapplied to the sheet (10′) via apertures (66). Finally, suction shouldnot normally be terminated at least until the clamping mechanism (70) isclamping the sheet (10′). However, while the vacuum should be terminatedbefore the clamping mechanism (70) begins to move the sheet (10′)towards the dispensing position (DP), this may not always be required,and in fact the vacuum may be provided continuously, whereupon theclamping mechanism (70) merely pulls away the sheet (10′) from thecylindrical member (60) against the suction force provided by thevacuum. In many practical applications, no adverse effects areencountered when operating the apparatus (100) with continuous vacuumprovided at the apertures (66).

[0090] Preferably, such synchronisations may be carried out undercomputer control using a suitable microprocessor operatively connectedto each of the elements—the pickup device (20) including the means forgenerating of the airstreams and creating the vacuum, and thecylinder-piston drive (40); the peeling mechanism (50), including theactuation mechanism (75) and driver; and the spraying system (300)—allof which are preferably electrically operated. Thus, the timing andduration of each element of the operations may be individuallycontrolled, as required, providing flexibility of operation, accordingto need or desire.

[0091] Alternatively, and as illustrated with respect to the firstembodiment of the apparatus (100) in FIGS. 1 to 6, synchronisation ofthe two operations may be accomplished mechanically. Thus, referring toFIGS. 1 and 4 in particular, pickup device (20) comprises upwardlyextending arms (25) each of which is pivotally attached to the pickuphead (22) and to a corresponding one of two projections or tabs (76),each of which extends diametrically from the respective arm (75) of theclamping mechanism (70) with respect to the shaft (80). Further, thelower free end (42) of the piston drive (40) is pivotally mounted to thepickup head (22), and the upper end (44) is similarly pivotally mountedto the fixed point (110) of the housing (200). With this arrangement,and with suitable dimensions and profiles being chosen for theinteracting mechanical linkage components, the first operation may be atleast partially mechanically synchronised with the second operation.Thus, when the pickup head (22) is in the lowermost position gently overthe upper sheet (10′), the clamping mechanism (70), in particular thejaws (72) and support (73) are in the dispensing position (DP). As thepickup head (22) is moved upwards, the arms (25) cause a clockwiserotation of the arms (75) via the tabs (76) (referring to FIGS. 1 and 4)due to the linkage via the pivots. This has the effect of causing theclamping mechanism (70) to swing towards the clamping position (DP), andalso to provide a horizontal motion to the pickup head (22). A pair ofstruts (85) pivotally mounted to the housing (200) and the pickup head(22) in parallelogram arrangement facilitates these motions. The motionis reversible as the pickup head (22) is lowered towards the stack againfor the start of the next cycle.

[0092] While the apparatus and method of the invention has beendescribed herein as directed, initially, to the pick-up head beinglowered onto the stack, and particularly the upper sheet thereof, it isessential only to bring the two together. Thus, according to the presentinvention, the apparatus can be configured, additionally oralternatively, to provide the required relative movement to the stack orupper sheet such as to bring the upper sheet into proximity or contactwith the pick up head. Hence, the apparatus can be configured to raiseand displace the stack such as to position the upper sheet below thepick up head, such as when the pick up head generates the air streams,the free end of the upper sheet curls up and may be held onto the pickup head, in a similar manner to that described herein where only thepick up head moves with respect to the stack, mutatis mutandis.Similarly, both the pick up head and the stack may be configured to movesuch as to provide the required relative motion between the pick up headand the stack.

[0093] A similar situation also applies to the second operation, whereinthe peeling mechanism has been described as providing the necessarydisplacement to the sheet to peel it away from the stack. Alternativelythe apparatus, and particularly the stack, can also be configured toprovide the necessary motion to the stack, once the clamping means haveclamped the first end of the sheet, such that the stack moves away fromthe clamping means automatically peeling off the upper sheet therefrom.It is also clear that according to the invention, the second operationcan be performed by moving both the stack and the peeling mechanism asrequired to effect the peeling action, as described herein mutatismutandis. In such cases, the peeling mechanism comprises suitabledisplacement means for the stack.

[0094] Referring to FIGS. 8 to 13, a second and preferred embodiment ofthe dispensing apparatus of the present invention, comprises a pick-uphead (which also comprises the peelback or peeling mechanism), generallydesignated (500), comprised in a housing (not shown), and is similar tothe first embodiment of the invention as described herein, mutatismutandis, with the following differences.

[0095] In this embodiment, the suction means and the blowing means areoperatively connected. Thus, the pick-up head (500) comprises a casing(510) accommodating a fan (530), air blower, compressor or the like,with an air inlet (512) and an exhaust (520) operatively connected tothe fan (530) via appropriate passages in the casing (510). Thus, thefan (530) sucks in air via the inlet (512 and blows the air via theexhaust (520). A cylindrical member (540) having apertures (541) isprovided above and forward of the exhaust (520) and is in fluidcommunication with the air inlet (512) via side pipes (560) connected tothe casing (510). The air inlet (512) is thus operatively connected tothe suction apertures (541) to provide suction when the fan (530) isoperated, and the fan exhaust (520), in the form of a flattened nozzle,provides the required airstreams. As shown particularly in FIGS. 8,13(a), 13(c) and 13(d), a valve (550) is provided to the air inlet (512)to enable the supply of air to the fan (530) to be selectively switchedfrom the vacuum apertures (541) to the atmosphere, and vice versa. Thus,when the valve (550) is open, the fan (530) sucks air therethrough fromthe general atmosphere, while when the valve (550) is closed, the fancan only suck in air via the suction apertures (541), providing suctionthereat. Advantageously, the valve (550) comprises a hinged flaparrangement that seals against the inlet (512), such that rotationalmovements or other predetermined movements of the pickup head (500)causes the flap to open or close with respect to the inlet (512), asdescribed herein.

[0096] Thus, the fan (530) can operate continuously to provide therequired airstreams, and the properly synchronised valve (550) enablessuction to be provided to the apertures (541) when needed to hold theend of the sheet, as it curls over the cylindrical member (540).Similarly, suction may be terminated from the apertures (541) whenrequired by means of the valve (550), for the subsequent peel back orrelease of the sheet.

[0097] In this embodiment, and referring particularly to FIG. 13(a) to13(d), the means for grasping the sheet is in the form of a pair, butmay be one or a plurality of, laterally distanced stationary clampingmembers (570), which reversibly clamp against the cylindrical member(540) when they are brought into proximity, and unclamp when they aredistanced one from the other. The clamping members (570) are typicallyattached to the casing (510) via lateral arms (572). Alternatively, thearms (572) may be attached to the housing. In any case, theconfiguration of the clamping members (570), the arms (572) and theconnection of the arms (572) to the casing (510) or housing are such asto enable synchronization of the clamping movement with the motion ofthe pickup head (500), in particular to provide a clamping actionagainst the pickup head (500) after the head has separated the end ofthe sheet and is holding the same.

[0098] The pickup head (500) is pivoted about axis (590) for enablingswinging motion, and may additionally comprise means for raising orlowering the head from a stack of sheets (10). Alternatively, the headmay be pivoted from any other suitable fulcrum that provides therequired motion between the head and the sheets of the stack.

[0099] Thus, referring to FIGS. 13(a) and 13(b), the pickup head (500)is tilted as shown with the exhaust (520) in proximity to the uppermostsheet, and the inlet (512) higher than the exhaust (520), such that thevalve (550) is closed. When the fan is in operation, it receives air viathe suction holes (541) and provides airstreams via the exhaust (520).The airstreams separate the end (12) of the uppermost sheet of the stackin a similar to that described with respect to the first embodiment,mutatis mutandis. Preferably, the stack is oriented such that a cornerof the sheets (10) is aligned with the cylinder member (540), ratherthan an edge. This provides better separation performance, and alsorequires a narrower cylindrical member than when the end being separatedcomprises an edge of the sheet. After separating the corner (12) of theuppermost sheet (10), this is held against the cylindrical member (540)via the suction force provided by the apertures (541), such that thisend (12) is at least partially wrapped over the cylinder. The pickuphead (500) is then rotated about a suitable fulcrum, typically axis(590) such as to vertically displace it from the stack, and such as tobring the cylindrical member (540) into abutting contact with thestationary clamping members (570). Thus, the free end (12) of the sheet(10) is now clamped between the cylindrical member (540) and thestationary clamping members (570), and the valve (550) can besynchronized to then stop the suction to the apertures (541), typicallyby tilting the casing (510) sufficiently such that the valve opens, asillustrated in FIG. 13(c). In this embodiment, the peeling mechanism maybe incorporated in the pick up head, and include suitable means forswinging the pickup head (500) with respect to the stack, particularlyfor lifting the sheet from the stack by an upward and backward motionsuch as to minimize relative movement between the second end (11) of theuppermost sheet and the stack. At this point, the sheet (10) may bepulled out of the housing via a suitable window (599) provided in thecasing, which is partially indicated at (598) in FIG. 13(c).

[0100] If it is desired to impregnate the sheet with a suitablesolution, then, just before pulling the sheet, a spraying system,optionally similar to that described with respect to the firstembodiment, mutatis mutandis, but typically comprised in the head (500)between the fan (530) and the exhaust (520), may optionally be employedfor spraying a suitable liquid onto the sheet by means of airstreamsprovided by the fan (530). First, and referring to the position of thesheet in FIG. 13(c), the fan (230) is used once more to blow air to thesheet via the exhaust (520), such as to detach the second end (11) ofthe sheet (10) from the stack, as illustrated in FIG. 13(d), and to blowthe sheet towards a suitable location, such as for example a trough(595). This is done while the second end (12) of the sheet is stillsubstantially on the stack, by properly synchronizing the motion of thehead (500) with the action of the fan (530). Then, the spraying systemin the casing (510) is switched on, and the liquid is conveyed to thesheet via the airstreams provided by the fan (530). Alternatively, theoriginal action of blowing the sheet to trough (595) may be concurrentwith spraying the sheet with liquid. In either case, the sheet remainsclamped between the cylindrical member (540) and the stationary clampmembers (570) until it is retrieved by a user via the window (599). Thetrough (595) is useful in enabling liquid from the spray and from thesheet top be collected in an orderly manner, rather than allow drippingtherefrom within the housing.

[0101] Whether the sheets are collected wet or dry via window (599), theclamping force exerted between the clamping members (570) and thecylindrical member (540), while sufficient to hold the sheet and to peelthe same from the stack, is nevertheless easily overcome by the pullingaction of a user via the window (599).

[0102] The clamping mechanism may be adapted for starting a newdispensing cycle automatically after a sheet is taken therefrom by auser. For example, the clamping members (570) and cylindrical member(540) may have electrical contacts or the like, which when in directcontact with one another, provide a signal for the next dispensing cycleto begin. Such direct contact is only possible after the sheet isremoved. Alternatively, a photosensor or any other suitable means may beused for detecting the absence of a sheet between the clamping members(570) and the cylindrical member (540). Additionally or alternatively, anew cycle may begin only when requested by a user.

[0103] In a variant of the second embodiment, the function of theclamping members (570) may be performed by the holding means, i.e., bythe suction provided between the sheet and the cylindrical member (540)via suction apertures (541). In such a case, the fan (530) needs to beoperating continuously during the peeling action of the pick up head(which thus also constitutes the peeling mechanism), and the valve (550)needs to be closed during the same period. Thus, in some embodiments theclamping mechanism of the peeling mechanism may actually be constitutedby the holding means of the pick up head.

[0104] While in the foregoing description describes in detail only a fewspecific embodiments of the invention, it will be understood by thoseskilled in the art that the invention is not limited thereto and thatother variations in form and details may be possible without departingfrom the scope and spirit of the invention herein disclosed or exceedingthe scope of the claims.

1. Apparatus for dispensing sheets comprising: a) a support foraccommodating a stack of sheets in overlying parallel relationship; b) apickup device overlying said support and comprising: (i) blowing meansfor producing airstreams over one end of the upper sheet of a stack thatmay be accommodated by said support, such as to curl up said end andseparate a portion of said upper sheet including said end from thestack; and (ii) suitable holding means such as to hold at least part ofsaid portion abutted against said pickup device such that saidairstreams may be terminated; c) a peeling mechanism having a clampingmechanism for clamping the separated portion of the upper sheet andadapted for displacing at least a portion of the sheet in a peelingmotion with respect to a remainder of said stack that may beaccommodated by said support.
 2. Apparatus as claimed in claim 1,wherein said pickup head comprises a displacement arrangement forreciprocally moving said pickup device towards and away from the stackthat may be accommodated by said support.
 3. Apparatus as claimed inclaim 2, wherein said displacement arrangement is adapted for providingvertical as well as horizontal motion to said pickup device. 4.Apparatus as claimed in claim 3, wherein said pickup head is configuredto reciprocally rotate about a suitable axis such as to provide adesired vertical and horizontal movement to a part of said pickup head,wherein said part of said pickup head comprises said blowing means andsaid holding means.
 5. Apparatus as claimed in claim 2, wherein saiddisplacement arrangement comprises a piston driver that is electricallyactuable and controllable by any suitable electric, electronic orcomputer means.
 6. Apparatus as claimed in claim 1, wherein said holdingmeans comprises a suitable suction means.
 7. Apparatus as claimed inclaim 6, wherein said suction means comprises a cylindrical memberhaving suitable apertures operatively connected to a suitable suctionsource.
 8. Apparatus as claimed in claim 7, wherein said cylindricalmember is substantially aligned with said end of said upper sheet. 9.Apparatus as claimed in claim 8, wherein said blowing means comprisesuitable openings provided in a plenum chamber accommodated in said pickup head, said openings being operatively connected to a suitablecompressed air source such as to provide substantially tangentialairstreams with respect to said cylindrical member.
 10. Apparatus asclaimed in claim 9, wherein said compressed air source comprises an aircompressor arrangement, including a fan or air blower.
 11. Apparatus asclaimed in claim 10, wherein said suction means and said blowing meansare operatively interconnected.
 12. Apparatus as claimed in claim 10,wherein said air compressor arrangement is electrically actuable andcontrollable by any suitable control means including electric,electronic or computer means.
 13. Apparatus as claimed in claim 7,wherein said vacuum source comprises a suitable vacuum pump, ejector orsuction pump arrangement.
 14. Apparatus as claimed in claim 13, whereinsaid pump arrangement is electrically actuable and controllable by anysuitable control means including electric, electronic or computer means.15. Apparatus as claimed in claim 1, wherein said clamping mechanismcomprises a support member having clamping means at each end thereofadapted for clamping said separated portion of said upper sheet, and apair of arms substantially orthogonal to said support member pivotallymounted with respect to a suitable swinging axis.
 16. Apparatus asclaimed in claim 15, wherein said clamping means comprise suitable jaws.17. Apparatus as claimed in claim 16, wherein said clamping meanscomprise a substantially stationary clamping member adapted for clampingwith respect to said cylinder after said pickup head separates and holdsan end of an upper sheet.
 18. Apparatus as claimed in claim 16, whereinsaid jaws are electrically actuable and controllable by any suitablecontrol means including electric, electronic or computer means. 19.Apparatus as claimed in claim 15, wherein said clamping mechanism isdisplaceable by means of a suitable driving mechanism.
 20. Apparatus asclaimed in claim 19, wherein said driving mechanism is electricallyactuable and controllable by any suitable control means includingelectric, electronic or computer means.
 21. Apparatus as claimed inclaim 15, wherein said peeling mechanism is suitably synchronised withsaid pickup device.
 22. Apparatus as claimed in claim 21, wherein saidsynchronisation is provided by suitable mechanical means.
 23. Apparatusas claimed in claim 21, wherein said synchronisation is provided bysuitable synchronisation means including electrical, electronic orcomputer means.
 24. Apparatus as claimed in claim 1, wherein saidsupport comprises a tray.
 25. Apparatus as claimed in claim 24, whereinsaid tray is in horizontal alignment.
 26. Apparatus as claimed in claim25, wherein said tray is horizontally reversibly movable from a positionoutside the apparatus to a position inside the apparatus.
 27. Apparatusas claimed in claim 1, further comprising a suitable spraying system forspraying at least one suitable liquid to a said sheet, said sprayingsystem being operatively connected to at least one source of saidliquids and comprising at least one nozzle adapted for spraying said atleast one liquid.
 28. Apparatus as claimed in claim 27, wherein saidspraying system is adapted for spraying a said sheet after the sheet hasbeen substantially fully separated from the said stack.
 29. Apparatus asclaimed in claim 27, wherein said spraying system is suitablysynchronised with at least with said peeling system.
 30. Apparatus asclaimed in claim 29, wherein said synchronisation is provided bysuitable mechanical means.
 31. Apparatus as claimed in claim 30, whereinsaid mechanical means comprises suitable mechanical linkage between saidpickup device and said peeling mechanism.
 32. Apparatus as claimed inclaim 29, wherein said synchronisation is provided by suitablesynchronisation means including electrical, electronic or computermeans.
 33. Apparatus as claimed in claim 27, wherein said sprayingsystem further comprising suitable means for enabling any desiredcombination of said liquids to be sprayed in any desired relativeproportions onto said sheet.
 34. Apparatus as claimed in claim 27,wherein said spraying system is operatively connected to said blowingmeans, wherein said blowing means generate suitable airstreams to carrysaid liquid to said sheet.
 35. Apparatus as claimed in claim 34, whereinsaid spraying system is suitably synchronized with said blowing meanssuch as to enable a sheet to be sprayed after the sheet has been fullyseparated from the said stack.
 36. Apparatus as claimed in claim 1,wherein said holding means constitute said clamping mechanism. 37.Apparatus as claimed in claim 1, wherein said peeling mechanism isincorporated in said pick up head.
 38. Apparatus as claimed in claim 37,wherein said peeling mechanism includes suitable means for swinging thepickup head with respect to the stack.
 39. Method for dispensing sheetsfrom a stack of sheets in overlying substantially parallel relationship,comprising: (a) providing suitable airstreams over a first end of anupper sheet of the stack such as to curl up said first end and separatea portion of said upper sheet including said first end from the stack;(b) creating a suitable holding force such as to hold said first endabutted against a suitable pickup device, and terminating the saidairstreams; (c) clamping the separated portion of the upper sheet in (b)and terminating the holding force; (d) displacing at least a part of thesheet in a peeling motion with respect to a remainder of said stack. 40.Method as claimed in claim 39, wherein in step (d) said at least a partof the sheet is displaced in a direction substantially towards a secondend of said upper sheet opposed to said first end of the sheet. 41.Method as claimed in claim 39, wherein said holding force comprises asuction force.
 42. Method as claimed in claim 39, wherein in step (d)all of said sheet is displaced in a peeling motion from said stack. 43.Method as claimed in claim 40, wherein a remaining part of said sheetwhich is still in overlying relationship with said stack is removed fromthe stack by providing a force to the sheet in a direction substantiallytowards said first end.
 44. Method as claimed in claim 43, wherein saidforce is provided by generating suitable airstreams to impinge on saidsheet.
 45. Method as claimed in claim 39, wherein said first endcomprises an edge of said sheet.
 46. Method as claimed in claim 39,wherein said first end comprises a corner of said sheet.
 47. Method asclaimed in claim 39, further comprising the step (e) of impregnating theseparated sheet with at least one suitable liquid after the sheet hasbeen separated.
 48. Method as claimed in claim 39, further comprisingthe step (f) of releasing the separated sheet for collection or furtherprocessing.
 49. Method as claimed in claim 39, wherein step (a) iseffected by bringing together a suitable pickup and said upper sheet,said blowing means comprising a cylindrical member having suitableopenings for providing said airstreams.
 50. Method as claimed in claim49, wherein said pickup device is lowered onto device until it restsgently on said upper sheet.
 51. Method as claimed in claim 49, whereinsaid upper sheet is raised until it is in gentle contact with said pickup device.
 52. Method as claimed in claim 40, wherein said suction forcein step (b) is provided via suitable apertures in said pickup deviceoperatively connected to a suitable vacuum source.
 53. Method as claimedin claim 39, wherein step (c) is effected by means of a suitable peelingmechanism including a clamping mechanism having a pair of opposedclamping means adapted for clamping said separated portion of said uppersheet, and a pair of arms extending orthogonally from said jaws andpivotally mounted with respect to a suitable swinging axis.
 54. Methodas claimed in claim 53, wherein said clamping means are in the form ofjaws.
 55. Method as claimed in claim 47, wherein step (e) is effected bymeans of a spraying system adapted for spraying said liquid to theseparated sheet.
 56. Method as claimed in claim 39, wherein steps (a) to(d) are synchronised with respect to one another.
 57. Method as claimedin claim 47, wherein at least steps (d) to (e) are suitably synchronisedwith respect to one another.
 58. Method as claimed in claim 55, whereinsteps (a) to (d) are at least partially synchronised by any suitablemechanical means.
 59. Method as claimed in claim 58, wherein saidmechanical means includes suitable mechanical linkage between saidpickup device and said peeling mechanism.
 60. Method as claimed in claim55, wherein said synchronisation is provided by suitable synchronizationmeans including electrical, electronic or computer means.
 61. Method asclaimed in claim 57, wherein said synchronisation is provided bysuitable synchronization means including electrical, electronic orcomputer means.